Multiscale Crystal Defect Dynamics (MCDD) – Towards an Atomistic-informed Crystal Plasticity
Abstract
In this lecture, the speaker will present the theoretical and computational formulation of a Multiscale Crystal Defect Dynamics (MCDD) that is basically an atomistically-informed dislocation pattern dynamics. The main novelties of the proposed MCDD are that: (1) He uses the dual-lattice tessellation to construct a pre-defect process zone model that can represent different types of crystal defects in a single crystal; (2) He adopts a fourth-order (four scales) Cauchy-Born-rule based strain gradient theory to model constitutive behaviors of various defect process zones, and that (3) He employs the Barycentric finite element technique to construct finite element shape functions for polygonal and polyhedral process zone elements. The proposed MCDD method provides an efficient and viable alternative for both molecular dynamics (MD) and dislocation dynamics (DD) in simulations of dislocation pattern evolutions, and crystal plasticity. In particular, MCDD offers a mesoscale description for dynamic lattice microstructure, defect microstructure, and their interactions. The method offers a possible solution for studying nanoscale and mesoscale crystalline plasticity.
About the speaker
Prof. LI Shaofan received his PhD in Mechanical Engineering from Northwestern University in 1997. He joined the University of California, Berkeley in 2000 and is currently a Professor at the Department of Civil and Environmental Engineering.
Prof. Li’s research focuses on atomistic and multiscale simulations, bio-mechanics and bio-physics, computational mechanics, micromechanics and nanomechanics of materials, soft matter mechanics and physics.
Prof. Li received numerous awards including the IACM (International Association for Computational Mechanics) Fellows Award (2018), and the US National Science Foundation CAREER Award (2003). He was also elected a fellow of the United States Association for Computational Mechanics in 2013.
